circadian rhythm comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
SR9009 is often grouped with compounds studied for circadian and metabolic regulation rather than with classical anabolic steroids. Its interactions with nuclear receptors differ from those of androgen receptor ligands, and its proposed mechanisms involve transcriptional control rather than direct hormone signaling. Some sources classify it as a metabolic modulator because of observed effects on energy utilization. The distinction matters for regulation and for interpreting research results across different compound classes.
SR9009 is a synthetic small molecule developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
Scientific discussion of SR9009 often separates animal evidence from human anecdote. Rodent studies provide controlled data on endurance, metabolism, and gene expression, but they use specific strains, doses, and treatment durations. Human reports are mostly uncontrolled and cannot establish cause and effect. Open questions include oral bioavailability, tissue distribution, metabolic stability, and long-term effects. Review articles generally call for more rigorous pharmacokinetic and safety research before any clinical use could be considered.
Analytical methods for SR9009 typically rely on liquid chromatography coupled with tandem mass spectrometry. The technique can separate the parent compound from related substances and detect low concentrations in biological matrices. Urine and blood are common samples in anti-doping testing, while in vitro studies may use cell culture media. Rapid metabolism and low expected concentrations make method validation important for reliable identification. Exact metabolite patterns can vary by species and are not fully mapped.
Regulatory treatment of SR9009 reflects its investigational status. The compound has no approved human therapeutic indication, and sports authorities prohibit its use. It appears on anti-doping lists as a non-approved substance or metabolic modulator, depending on the list version. Products sold online as research chemicals are not quality-controlled medicines, so their identity and purity can differ from the label. Such products may also contain unlisted compounds, which complicates both testing and safety assessment.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Reported for the free base |
| Molecular weight | 437.9 g/mol | Calculated from the formula |
| Primary target | REV-ERBα and REV-ERBβ | Nuclear receptors involved in circadian regulation |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water |
| Typical storage | -20 °C, desiccated | Protect from light and moisture |
Mechanistically, SR9009 binds the ligand-binding domain of REV-ERBα/β and enhances recruitment of corepressor complexes. This represses target genes rather than activating them. Because REV-ERB proteins normally compete with ROR proteins at shared response elements, the net effect depends on tissue and timing. Researchers use SR9009 to probe how nuclear receptor signaling links the clock to metabolism, inflammation, and muscle biology. Findings are largely preclinical, and the precise contribution of each receptor subtype remains under study.
SR9009 is frequently discussed in fitness and research-chemical contexts, yet it has no approved medical indication. Regulatory agencies have not authorized it for human use, and it is not a standard prescription drug. Some sports organizations list it as a prohibited substance because of its potential performance-enhancing properties. Published human data are sparse, so claims about its effects in people often rely on animal models or anecdotal reports. Quality and identity of online materials can vary widely.
SR9009 is a synthetic small molecule studied as a REV-ERB agonist. REV-ERBα and REV-ERBβ are nuclear receptors that help regulate circadian rhythms and metabolic gene expression. The compound was identified in academic screening efforts to find synthetic ligands for these receptors. In cell and animal studies, SR9009 alters transcription of genes involved in lipid and glucose metabolism, and it can shift circadian behavior. It is not an approved therapeutic agent.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
Laboratory studies often administer SR9009 by injection because oral absorption appears poor in rodents. Reported pharmacokinetic properties include rapid metabolism and low systemic exposure after oral dosing. Human pharmacokinetic data are sparse, so absorption, distribution, metabolism, and excretion in people are not well defined. Some research explores related REV-ERB compounds with improved drug-like properties. Regulatory approval for any REV-ERB agonist as a human medicine has not been granted to date.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ, also called NR1D1 and NR1D2. These receptors help regulate circadian rhythms and metabolic gene programs. The compound was developed for laboratory research, not as an approved therapeutic. Its identity is distinct from steroid hormones and selective androgen receptor modulators. Scientific interest centers on how REV-ERB activation changes gene expression in cells and animal models.
==== Electrochemical biosensor ==== Electrochemical sensor convert biological information into electrical signals that could be detected. The conductivity and biocompatibility of Au NP allow it to act as "electron wire". It transfers electron between the electrode and the active site of the enzyme. It could be accomplished in two ways: attach the Au NP to either the enzyme or the electrode. GNP-glucose oxidase monolayer electrode was constructed use these two methods. The Au NP allowed more freedom in the enzyme's orientation and therefore more sensitive and stable detection. Au NP also acts as immobilization platform for the enzyme. Most biomolecules denatures or lose its activity when interacted with the electrode. The biocompatibility and high surface energy of Au allow it to bind to a large amount of protein without altering its activity and results in a more sensitive sensor. Moreover, Au NP also catalyzes biological reactions. Gold nanoparticle under 2 nm has shown catalytic activity to the oxidation of styrene.
Serbia, and in particular the valley of the Morava is often described as "the crossroads between the East and the West" – one of the primary reasons for its turbulent history. The valley is by far the easiest land route from continental Europe to Greece and Asia Minor. Major international highways going through Serbia were E75 and E70. E763/E761 was the most important route connecting Serbia with Montenegro. The Danube, an important international waterway, flowed through Serbia. The Port of Bar was the largest seaport located in Montenegro.
=== Risk factors === A number of factors can potentially increase the risk of developing paracetamol toxicity. Chronic excessive alcohol consumption can induce CYP2E1, thus increasing the potential toxicity of paracetamol. In one study of patients with liver injury, 64% reported alcohol intakes of greater than 80 grams a day, while 35% took 60 grams a day or less. Whether chronic alcoholism should be considered a risk factor has been debated by some clinical toxicologists. For chronic alcohol users, acute alcohol ingestion at the time of a paracetamol overdose may have a protective effect. For non-chronic alcohol users, acute alcohol consumption had no protective effect. Fasting is a risk factor, possibly because of depletion of liver glutathione reserves. The concomitant use of the CYP2E1 inducer isoniazid increases the risk of hepatotoxicity, though whether 2E1 induction is related to the hepatotoxicity in this case is unclear. Concomitant use of other drugs that induce CYP enzymes, such as antiepileptics including carbamazepine, phenytoin, and barbiturates, have also been reported as risk factors.
Setipiprant (INN; developmental code names ACT-129968, KYTH-105) is an investigational drug developed for the treatment of asthma and scalp hair loss. It was originally developed by Actelion and acts as a selective, orally available antagonist of the prostaglandin D2 receptor 2 (DP2). The drug is being developed as a novel treatment for male pattern baldness by Allergan.
=== Changes that occur during the onset of gingivitis and periodontitis and its role in bleeding on probing === Following the infiltration of bacteria and its products within the sulcular epithelium, the inflammatory response triggers the release of matrix metalloproteinases which cause collagen destruction. Studies suggest that this mechanism is through the activation of Toll-Like Receptors (TLRs, such as TLR-9) which are present on epithelial cells upon binding with bacterial products (such as lipopolysaccharides, unmyelinated CpG motifs). The expression of these collagenolytic matrix metalloproteinases like MMP-13 and activated NF-κB subunit p65 (a type of transcription factor) was more commonly present in periodontitis tissue compared to gingivitis tissue, indicating that the extent of connective tissue destruction accelerates with the progression of the disease. As an effort to curb the incoming bacterial invasion, the basal cells of the sulcular epithelium, being triggered by the ongoing inflammation, proliferate in hopes to maintain an intact barrier against the bacteria and their products. Due to the ongoing inflammation, engorgement of vessels and vasodilation occurs at the underlying connective tissue of the sulcular epithelium. The concurrent destruction of the collagen will then result in the thinning or ulceration of the sulcular epithelium, making the engorged and more abundant blood capillaries more susceptible to rupture upon innocuous mechanical stimuli (such as those during toothbrushing, probing, flossing, eating).
Sources: en.wikipedia.org
=== Visual effects === Zoic Studios provided visual effects for the series. According to Johns, Stargirl was the first Warner Bros. Television series to use previsualization (a process most commonly used by feature films) for their effects scenes. Previsualization was handled by The Third Floor, Inc. Johns brought his experience working on the films Wonder Woman (2017), Aquaman (2018), and Shazam! (2019) to help the series have visuals not "seen in superhero shows before".
== Plantations == Blue gum is one of the most extensively planted eucalypts. Its rapid growth and adaptability to a range of conditions is responsible for its popularity. It is especially well-suited to countries with a Mediterranean-type climate, but also grows well in high altitudes in the tropics. It comprises 65% of all plantation hardwood in Australia with approximately 4,500 km2 (1,100,000 acres) planted. In about 1860 Francis Cook planted the tree on the Monserrate Palace, his property at Sintra in Portugal. By 1878 the tree "had spread from one end of Portugal to the other". E. globulus began to be planted as plantations in Los Lagos and Los Ríos regions of Chile in the 1990s. However at these latitudes around the 40th parallel south the tree is at the southern border of the climatic conditions where it can grow, hence good growth in this part of southern Chile requires good site selection such as sunny north-facing slopes. Some of these plantations grow on red clay soil.
=== Industrial origin === Perchlorates are used mostly in rocket propellants but also in disinfectants, bleaching agents, and herbicides. Perchlorate contamination is caused during both the manufacture and ignition of rockets and fireworks. Fireworks are also a source of perchlorate in lakes. Removal and recovery methods of these compounds from explosives and rocket propellants include high-pressure water washout, which generates aqueous ammonium perchlorate.
A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nucleotides. By convention, sequences are usually presented from the 5' end to the 3' end. For DNA, with its double helix, there are two possible directions for the notated sequence; of these two, the sense strand is used. Because nucleic acids are normally linear (unbranched) polymers, specifying the sequence is equivalent to defining the covalent structure of the entire molecule. For this reason, the nucleic acid sequence is also termed the primary structure. The sequence represents genetic information. Biological deoxyribonucleic acid represents the information which directs the functions of an organism. Nucleic acids also have a secondary structure and tertiary structure. Primary structure is sometimes mistakenly referred to as "primary sequence". However there is no parallel concept of secondary or tertiary sequence.
Sources: en.wikipedia.org
=== Che–Cl === Zhijian James Chen (b. 1966). Chinese-American biochemist at the University of Texas Southwestern Medical Center, known discovering mechanisms by which nucleic acids trigger innate and autoimmune responses from the interior of a cell. Member Natl. Acad. Sci. USA. Albert Chibnall FRS (1894–1988), British biochemist known for his work on the nitrogen metabolism of plants. Ruth Chiquet-Ehrismann (1954–2015), Swiss biochemist and cell biologist working on interactions in the extracellular matrix. Cyrus Chothia FRS (1942–2019). British biochemist at Cambridge known for work on protein structure. Gilbert Chu (b. 1946). American biochemist at Stanford, known for investigating how cells react to DNA damage from radiation. George M. Church (b. 1954). American geneticist at Harvard and MIT, known for pioneering personal genomics and synthetic biology. Member Natl. Acad. Sci. USA. Aaron Ciechanover (b. 1947). Israeli biochemist at the Technion, Haifa, known for work on protein turnover. Nobel Prize for Chemistry in 2004. Foreign associate Natl. Acad. Sci. USA. Vintilă Ciocâlteu (1890–1947) Roumanian physician, biochemist, researcher, professor, and author. Hans Thacher Clarke (1887–1972), British-born American biochemist at Columbia University, known for the Eschweiler–Clarke reaction. Member Natl. Acad. Sci. USA. Jane Clarke (b. 1950). Biochemist at Cambridge known for work on folding and assembly of proteins. Steven Clarke (b. 1949). American biochemist at UCLA, known for work on molecular damage and molecular repair mechanisms. Roy Elwood Clausen (1891–1956).
The rate at which heat is removed by melting one short ton (910 kg) of ice in 24 hours is called a ton of refrigeration, or even a ton of cooling. This unit of refrigeration capacity came from the days when large blocks of ice were used for cooling, and is still used to describe the heat-removal capabilities of refrigerators and chillers today. One ton of refrigeration is exactly equal to 12,000 BTU/h, or 3.517 kW.
Adenosine production and lack of ammonia overproduction seem to strongly suppress rhabdomyolysis down to the purine nucleotide energy charge level, where the cell is able to signal pain, or where individual muscle fibers start cramping (fail to relax from contraction in sync with the rest of the muscle), or the whole muscle fails to contract (when walking quickly downhill), allowing the person to appropriately modulate the exertion. Most of the AMP probably spills into blood unchanged, and is gradually returned to the muscle cell, if its concentration there falls due to gradual recharge to ATP. The blood thus plays a role of a big AMP buffer. Idle muscles may also take up some free AMP. The spillover also limits, how much the residual AMPD activity can be amplified in this state. Thus, it may take the residual AMPD activity less time to build up citric acid cycle intermediates, when the whole body is warmed up for an exercise at the same time, rather than a specific group of muscles needed in the exercise. In case of leg muscles, where circulation is substantially dependent on their cyclical contraction when the body is upright, a small but useful degree of initial up-regulation of the citric acid cycle may be achieved just by standing still for a few minutes. It is most useful when a long period of rest, or sitting in a vehicle, must be followed by brisk walking. If the person keeps standing still for longer, rather than restoring circulation in the leg muscles (e.g.
The fund bought the remaining 80% of Truist, together with Stone Point Capital, Clayton, Dubilier & Rice and other investors, for $15.5 billion in 2024. In May 2023, Mubadala agreed to buy a majority stake in a New York–based Fortress Investment Group from the SoftBank Group. The $3 billion takeover was intended to be closed in the first quarter of 2024. However, the deal that would give Mubadala 70% stakes in Fortress was being scrutinized by the U.S. national security officers. The deal, which raised concerns for the US over the UAE's ties with China, was being closely reviewed by the Committee on Foreign Investment in the US (Cfius). In May 2024, the regulatory body approved of the sale. A year later in April 2025, Mubadala and Fortress Investment started a $1 billion investment partnership. Mubadala increased its partnership with Aldar Properties in September 2024 with four joint ventures amounting to more than $8.2 billion across Abu Dhabi. In September 2024, Turkish Competition Authority confirmed that Mubadala applied to acquire Getir in entirety. In June 2024, Getir founders, Nazim Salur and Serkan Borancili, opposed Mubadala's restructuring plan that would separate profitable local grocery delivery operations with noncore businesses. Under the proposed plan, Mubadala was to acquire grocery delivery operations in exchange for $250 million investment. However, in January 2025, Salur alleged Mubadala of an “illegal coup” and vowed to take legal action against the Emirati firm.
Dichloroacetic acid (DCA), sometimes called bichloroacetic acid (BCA), is the organic compound with formula CHCl2CO2H. It is an analogue of acetic acid, in which 2 of the 3 hydrogen atoms of the methyl group have been replaced by chlorine atoms. Like the other chloroacetic acids, it has various practical applications. The salts and esters of dichloroacetic acid are called dichloroacetates.
Sources: en.wikipedia.org
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.
It binds to REV-ERBα and REV-ERBβ, nuclear receptors involved in circadian and metabolic gene regulation. This can alter transcription of genes related to lipid and glucose metabolism in experimental models.
No controlled human trials have established that effect. Endurance findings come primarily from rodent studies, and human responses remain unknown.
No. It is an investigational compound without approved therapeutic indications. It is sold for research purposes only in many jurisdictions.